Recording medium for storing virtually deleted still picture information, recording and/or reproducing method and apparatus therefor

ABSTRACT

A recording medium for storing virtual deletion information, and recording and/or reproducing method and apparatus therefor are provided. The recording medium includes a first region having a plurality of still pictures, and a second region having first virtual deletion information for the still pictures, and still picture group information for separating the still pictures in the first region into a predetermined maximum number of groups in order to manage the still pictures at a group level, wherein the first virtual deletion information is within the still picture group information, and if the first virtual deletion information is set to a virtual delete state, the corresponding still picture is not to be reproduced. Accordingly, file extent information can be prevented from excessively increasing by maximally preventing a recording area from being scattered, when some of a data file are deleted by a user&#39;s request.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a divisional of application Ser. No.09/339,190, filed Jun. 24, 1999, now pending, and claims the benefit ofKorean Application No. 98-23991, filed Jun. 24, 1998 and KoreanApplication No. 98-44804, filed Oct. 26, 1998, in the Korean PatentOffice, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to recording and/or reproducinginformation, for effectively processing a still picture, and moreparticularly, to a recording medium for storing virtual deletioninformation for preventing file extent information from excessivelyincreasing when some of a data file is deleted by a user's request, andrecording and/or reproducing method and apparatus therefor.

[0004] 2. Description of the Related Art

[0005]FIG. 1 shows a connection structure for various kinds ofinformation in a moving picture and moving picture data, inrecording/reproducing audio and/or video data on a recordable and/orrewriteable recording medium, specifically, a digital versatile disk(DVD), and more precisely, it illustrates the relationship betweenprogram chain (PGC) information 11 for treating data logically, movingpicture information 12 including video object (VOB) information, and amoving picture data file 13 in which actually compressed audio/video(A/V) data are recorded in VOB units.

[0006] First, terms used throughout the specification will now bedescribed. Supposing a movie was recorded in first and second parts, theoverall movie is a program chain (PGC) and the first and second partsare programs. Also, each program can be defined by further dividing thesame into several cells called sub-units. The information in each cellcan wholly or partially define a video object (VOB). In such an event,each cell is used as a basic accessing unit during reproduction, and theprogram and PGC are only the information for connectivity between aplurality of cells.

[0007] Also, since data is actually sub-divided into video object units(VOBUs) and recorded in a moving picture data file, the VOB informationincludes various kinds of information relating to the VOBU data, thatis, VOBU #1, VOBU #2, . . . and the VOB data in the moving picture datafile is accessed by the VOB information. Here, the VOB data is used as arandom access unit of a disk recording/reproducing apparatus. The VOBUis based on a single GOP (Group of Pictures) in the case of an MPEG(Moving Picture Experts Group) video, and audio data corresponding tovideo data is collected, that is, A/V data is multiplexed into sectors,to constitute a VOBU.

[0008] The data format shown in FIG. 1 is concerned with the movingpicture, in which the unit of actual data, the VOB, comprises movingpicture data for a fixed period of time. Synchronization or encoding ofA/V signals is performed in units of VOBs. However, in the case of astill picture, each VOB constitutes a still picture. When a VOB isdesignated in a cell structure, a cell is necessary for each stillpicture. Thus, as more still pictures are recorded, more information isadded.

[0009] Generally, data errors may be generated if data is recorded on arecordable disk a predetermined number of times. Thus, there is a limitin the number of times for rewriting data on a disk. All information isstored in the memory of a controller for controlling the system for thepurpose of limiting the number of recording times and rapidly accessingdata. However, as described above, in the case of a still picture, ifthe amount of information is increased, much time is required forreading the information. Also, there is a limit to the amount ofinformation that can be stored in a memory with a limited size.Accordingly, it is not possible to record a large-capacity stillpicture.

[0010] In a two-dimensional recording medium such as a disk, a file maybe distributed in physically fragmented spaces to then be recorded, andinformation which connects the scattered areas is recorded in a filesystem as file extent information. File extent information isinformation for logically connecting a file having the scattered areasand generally represents the scattered areas sequentially as startpositions and lengths of data. Referring to FIG. 2, for example, a fileis distributed and recorded in two parts, each represented by a startposition and length of data in the file extent information. If a portionindicated by “A” shown in FIG. 2 is deleted so that the file isdistributed in three parts, the amount of file extent information isincreased, as shown in FIG. 3.

[0011] In other words, as shown in FIG. 3, the amount of file extentinformation is determined according to the level of fragmentation of afile, irrespective of the size of the file. Therefore, when a pluralityof still pictures are recorded in a file, if some still pictures aredeleted by a user's request, thus causing fragmentation of the file, theamount of the file extent information is sharply increased.

SUMMARY OF THE INVENTION

[0012] To solve the above problems, it is a first object of the presentinvention to provide a recording medium for grouping a plurality oflarge-capacity still pictures for the purpose of managing the same at astill picture group level, and for storing still picture groupinformation containing information for virtually deleting a desiredstill picture.

[0013] It is a second object of the present invention to provide arecording medium for grouping a plurality of additional audio data otherthan original audio data added to still picture data, for the purpose ofmanaging the same at an additional audio group level, and for storingadditional audio group information containing information for virtuallydeleting additional audio data.

[0014] It is a third object of the present invention to provide arecording and/or reproducing method and apparatus for grouping aplurality of a large-capacity still pictures and incorporating virtualdeletion information into the information managed at a still picturegroup level for the purpose of virtually deleting a desired stillpicture and original audio data corresponding thereto.

[0015] It is a fourth object of the present invention to provide arecording and/or reproducing method and apparatus for grouping aplurality of additional audio data relating to still pictures andincorporating virtual deletion information into the information managedat an additional audio group level for the purpose of virtually deletingthe additional audio data corresponding to the virtually deleted stillpicture.

[0016] Additional objects and advantages of the invention will be setforth in part in the description which follows and, in part, will beobvious from the description, or may be learned by practice of theinvention.

[0017] To achieve the first object, there is provided a recording mediumincluding a first region having a plurality of still pictures, and asecond region having first virtual deletion information for the stillpictures, and still picture group information for separating the stillpictures in the first region into a predetermined maximum number ofgroups in order to manage the still pictures at a group level, whereinthe first virtual deletion information is within the still picture groupinformation, and if the first virtual deletion information is set to avirtual delete state, the corresponding still picture is not to bereproduced.

[0018] To achieve the second object, there is provided a method forrecording and/or reproducing audio and/or video data on a recordableand/or rewriteable recording medium including (a) recording a pluralityof input still pictures, and (b) separating the plurality of stillpictures into a predetermined maximum number of groups, and recordingstill picture group information having first virtual deletioninformation for the respective still pictures set to a virtual deletestate by a user and playback information related to reproduction.

[0019] Also, the method according to the invention further includes thesteps of reading the still picture group data to be reproduced inaccordance with the playback information, and calculating the positionof a desired still picture in accordance with the read still picturegroup data and reproducing still picture data located at the calculatedposition, while not reproducing still picture data having the firstvirtual deletion information contained in the read still picture groupdata set to a virtual delete state.

[0020] The apparatus according to the present invention includes arecording processor for signal-processing a plurality of still picturesto be recorded in a first region of the recording medium, and acontroller for controlling first virtual deletion information for stillpictures set to a virtual delete state by a user, the first virtualdeletion information contained within still picture group informationfor separating the still pictures in the first region into within apredetermined maximum number of groups in order to manage the stillpictures at a group level, for generating playback information relatedto a reproduction order, and for controlling the generated playbackinformation to be recorded in a second region of the recording medium.

[0021] According to another aspect of the invention, the apparatusfurther includes a playback processor for reproducing still picture datain the first region based on the still picture group information in thesecond region, while not reproducing still picture having the firstvirtual deletion information set to a virtual delete state.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above objects and advantages of the present invention willbecome more apparent by describing in detail preferred embodimentsthereof with reference to the attached drawings in which:

[0023]FIG. 1 illustrates a connection structure for various kinds ofinformation and data in a moving picture;

[0024]FIG. 2 shows an example of file recording positions and fileextent information;

[0025]FIG. 3 illustrates the relationship between the distribution of afile and the file extent information;

[0026]FIG. 4 shows an example of an overall information structure of arecording medium according to the present invention;

[0027]FIG. 5 shows the relationship between various kinds of informationand still picture data in a still picture according to the presentinvention;

[0028]FIG. 6 is a block diagram of a recording/reproducing apparatusaccording to the present invention;

[0029]FIG. 7 shows the relationship between still picture data and stillpicture group information according to the present invention;

[0030]FIG. 8 shows the relationship between additional audio data addedto still picture data and additional audio group information accordingto the present information;

[0031]FIG. 9 shows the relationship between cell information and stillpicture group information;

[0032]FIG. 10 shows the relationship among cell information, stillpicture group information and additional audio group information;

[0033]FIG. 11 illustrates a virtually deleted still picture file andstill picture group information in accordance with a still picturedeletion command;

[0034]FIG. 12 illustrates a virtually deleted additional audio data fileand additional audio group information in accordance with a stillpicture deletion command;

[0035]FIG. 13 illustrates actual deletion of a still picture file andstill picture group information in accordance with a deletion commandfor all still pictures in a still picture group;

[0036]FIG. 14 illustrates actual deletion of an additional audio datafile and additional audio group information in accordance with adeletion command for all still pictures in an additional audio group;

[0037]FIG. 15 illustrates the structure of still picture groupinformation according to the present invention;

[0038]FIG. 16 is a table showing an example of the detailed contents ofthe still picture group general information shown in FIG. 15;

[0039]FIG. 17 illustrates the structure of a map table for a stillpicture shown in FIG. 15;

[0040]FIG. 18 is a table showing an example of the detailed contents ofa video map in the map table shown in FIG. 17;

[0041]FIG. 19 is a table showing an example of the detailed contents ofan original audio map connected to the video map shown in FIG. 18;

[0042]FIG. 20 illustrates the structure of additional audio groupinformation for a still picture according to the present invention;

[0043]FIG. 21 is a table showing an example of the detailed contents ofadditional audio group general information for the still picture shownin FIG. 20;

[0044]FIG. 22 illustrates the structure of an additional audio map tablefor the still picture shown in FIG. 20;

[0045]FIG. 23 is a table showing an example of the detailed contents ofthe additional audio map table for the still picture shown in FIG. 22;

[0046]FIG. 24 is a table showing an example of the detailed contents ofcell information for the still picture shown in FIGS. 9 and 10;

[0047]FIGS. 25A and 25B illustrate a flow chart showing a method forrecording a still picture according to a first embodiment of a presentinvention;

[0048]FIG. 26 is a flow chart showing a method for recording additionalaudio data after recording a still picture according to the firstembodiment of the present invention;

[0049]FIG. 27 is a flow chart showing a method for reproducing a stillpicture according to the first embodiment of the present invention;

[0050]FIGS. 28A and 28B are flowcharts showing a method for reproducinga still picture according to a second embodiment of the presentinvention;

[0051]FIG. 29 is a flow chart showing a method for reproducing a stillpicture according to a third embodiment of the present invention; and

[0052]FIGS. 30A and 30B illustrate a flow chart showing a method fordeleting data using virtual deletion information according to thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] Hereinafter, preferred embodiments of recording media for storingvirtual deletion information for a still picture, and a recording and/orreproducing method and apparatus therefor, examples of which areillustrated in the accompanying drawings, wherein like referencenumerals refer to the like elements throughout. The embodiments aredescribed below in order to explain the present invention by referringto the figures.

[0054]FIG. 4 shows an example of an overall information structureaccording to the present invention, in which information including PGCinformation, moving picture information and still picture informationcan be recorded in an information file or an information area.

[0055] Here, PGC general information contains information such as thenumber of programs in a PGC. Program general information containsinformation such as the number of cells in a program. The cellinformation designates a VOB in the case of a moving picture, as shownin FIG. 1, and designates a still picture VOB group (to be abbreviatedas “still picture group” for brevity) instead of a VOB, in the case of astill picture, as shown in FIG. 5. Since the moving picture informationhas already been described with reference to FIG. 1, a descriptionthereof will be omitted herein and still picture information accordingto the present invention will now be described. Still picture generalinformation contains information relating to the number of kinds ofstill picture group information, and additional audio generalinformation for the still picture contains information relating to thenumber of kinds of additional audio group information.

[0056]FIG. 5 shows the connection structure of various kinds ofinformation and still picture data in a still picture. In other words,in a still picture recorded in units of VOBs in a data file, a pluralityof VOBs for still pictures are managed by a still picture group, andcell information contained in the PGC information 21 designates stillpicture group information (GVOB), rather than a single VOB information.Also, audio data may be recorded in addition to the still picture. Theaudio data is recorded consecutively after the still picture isrecorded, thereby reducing the search time of a reproducing head duringreproduction. The audio data recorded together with the still picture iscalled original audio data, which is contained in the still picturegroup. In the present invention, unless specifically defined, a stillpicture represents both one having only a video part and one having theoriginal audio part and the video part. By managing the still picture bygrouping the same in such a manner, the amount of cell information andstill picture information can be reduced. For example, video codingattributes or original audio coding attributes in a still picture groupare assimilated thus forming still picture group general information,and stored as common information. For the respective still pictures, thepositions thereof in the still picture data file must be indicated. Inthe case when the still pictures are not separated into a plurality ofgroups, the start positions of the respective still pictures must beindicated. However, in the case when the still pictures are grouped, thestart position at which the pertinent still picture group starts to berecorded in a file is stored in the still picture group generalinformation and then only the sizes of the respective still pictures arerecorded as the information for the respective still pictures. Since theamount of information indicative of the size of still picture data,i.e., the number of bytes, is generally less than that indicative of theposition in a file, the overall amount of information can be reduced.

[0057] A user may add separate additional audio data to a desired stillpicture after recording the still picture and original audio data on astill picture file 23. At this time, only the additional audio data arecollected and recorded in a separate area in the additional audio datafile 24 or the still picture file 23, with the original audio data beingretained. The additional audio data are also managed by grouping in thesame manner as in the still picture data and the concept thereof is thesame as that of the still picture data. In other words, a plurality ofadditional audio data having the same attributes, e.g., audio codingattributes, are grouped into an additional audio group (to beabbreviated as “GAOB”) and then additional audio group generalinformation is recorded as common information. For the respectiveadditional audio data AOBs, only the size information is recorded. Theadditional audio group general information contains the start positionsof audio data in the respective additional audio groups (GAOBs). Theconnection information for the additional audio data added to thespecific still picture, which is indicated by thick arrows in FIG. 5, ispresent in the still picture group information GVOB #1, GVOB #2, . . .In other words, additional audio group identification information fordesignating additional audio data existing in the still picture groupinformation and additional audio identification information in thepertinent additional audio group are contained in the still picturegroup information.

[0058] In order to locate a recording position of a specific stillpicture in the still picture group, the start position of the stillpicture group data contained in the still picture group generalinformation is added to the size of the data preceding the still pictureto be located. Likewise, in order to search the recording position ofspecific additional audio data, the start position of the additionalaudio group data contained in the additional audio group generalinformation is added to the size of the data preceding the additionalaudio data to be located.

[0059] In the case of a still picture group, video parts and audio partsare consecutively recorded in a file or space. Thus, the videoinformation and the audio information each containing the size thereofare also recorded in the bitstream order in which the video data and theoriginal audio data are actually recorded. In the case of an additionalaudio group, there is only the additional audio data. Thus, only theadditional audio information is recorded in the bitstream order in whichthe additional audio data is actually recorded.

[0060] Thus, as shown in FIG. 5, there is the still picture file 23 towhich the original audio data may be added, the additional audio datafile 24 added to the still picture and the information file containingthe PGC information 21 and the still picture information 22 having thestill picture group information (GVOB) and the additional audio groupinformation (GAOB). However, the additional audio data may be recordedin a separate area of the still picture file 23, rather than in theadditional audio data file 24. The still picture file 23 can bedesignated by a first region, the additional audio data file 24 can bedesignated by a second region, and the information file containing thePGC information 21 and the still picture information 22 can bedesignated by a third region which is a logic region.

[0061]FIG. 6 is a block diagram of a recording/reproducing apparatus forimplementing the present invention. The function of an apparatus forrecording/reproducing A/V (audio/video) data using a recordable andrewriteable disk is largely divided into recording and reproduction.

[0062] During recording, an AV codec 110 compression-codes an externallyapplied A/V signal by a predetermined compression scheme and suppliessize information for compressed data. A digital signal processor (DSP)120 receives A/V data supplied from the AV codec 110, adds additionaldata for ECC (error correction code) processing thereto and performsmodulation using a predetermined modulation scheme. A radio frequencyamplifier (RF AMP) 130 converts electrical data supplied from the DSP120 into an RF signal. A pickup 140 drives a disk and records the RFsignal supplied from the RF AMP 130, incorporating an actuator forfocusing and tracking. A servo 150 receives information necessary forservo control from a system controller 160 and stably performs a servofunction. The system controller 160 controls the overall system throughinterfacing with a user to thus control the still picture to be recordedon the disk and record separate information for the recorded stillpicture. Still picture data are managed at a group level by constructingthe still picture group information of the information for therespective still pictures, including size information of still picturedata, size information of original audio data, playback time informationof original audio data and the like, and the position information of therespective still pictures, in the recording order of recorded stillpictures and audio data. When additional audio data is added to a stillpicture, the added additional audio data is recorded in a different filefrom or in the same file as that for the still picture but in adifferent area from that of the still picture. Additional audio data aremanaged at a group level by constructing additional audio groupinformation of the information for recorded additional audio data,including size information of additional audio data, playback timeinformation of additional audio data and the like, and positioninformation of the respective additional audio groups. The informationfor the respective still pictures includes information indicative of theadded additional audio data.

[0063] In the case when a user intends to delete an arbitrary stillpicture via a user interface, the system controller 160 does not toactually delete the still picture but sets deletion information in thestill picture group information to a virtual delete state so that it isvirtually deleted. In other words, since data is not reproduced duringplayback although it actually exists, it appears to the user that thedata is deleted. In such a manner, if a specific still picture isvirtually deleted and original audio data is recorded in sequence withthe still picture, the original audio data is not reproduced either.Also, if additional audio data is added to the still picture, virtuallydeleted additional audio information in the additional audio groupinformation is set to a virtual delete state so that although theadditional audio data exists actually, it appears to the user that theadditional audio data is deleted.

[0064] Cell information concerning the reproduction order is recorded aswell as the above-described information. The cell information containsinformation indicative of the recorded still picture group so that therecorded still picture and audio data can be reproduced.

[0065] During playback, the pickup 140 picks up the optical signal fromthe disk having data stored therein and the data is extracted from theoptical signal. The RF AMP 130 converts the optical signal (that is, RFsignal) into electrical data, and extracts a servo signal for performinga servo function, and modulated data. The DSP 120 demodulates modulateddata supplied from the RF AMP 130 corresponding to the modulation schemeused during modulation, performs an ECC process to correct errors andeliminates added data. The servo unit 150 receives information necessaryfor servo control from the RF AMP 130 and the system controller 160 andstably performs a servo function. The AV codec 110 decodes thecompressed A/V data supplied from the DSP 120 to output an A/V signal.The system controller 160 controls the overall system for reproducingthe user's desired data (still picture only, still picture+originalaudio data or still picture+additional audio data) using the cellinformation and still picture group information stored on the disk whileperforming user interfacing such as processing of the user's key inputs.

[0066] In other words, in order to reproduce a specific still pictureand audio data, the still picture group information having the stillpicture to be reproduced is obtained from the cell information,information such as the size of the still picture data and theinformation for the data size and playback time of original audio data,if any, is obtained from the still picture group information, therebyreproducing only desired data. Also, if additional audio data is addedto the still picture, desired additional audio data is reproduced usinginformation for the data size or playback time of the additional audiodata from the additional audio group information pointed to by the stillpicture group information.

[0067] Also, if virtually deleted still picture information is read fromthe still picture group information, the corresponding still picture andoriginal audio data are not reproduced so that although the dataactually exists, it seems to the user that it does not exist. Likewise,if the added additional audio data is virtually deleted, it is notreproduced.

[0068] Here, the A/V codec 110, the DSP 120, the RF AMP 130 and thepickup 140 operating during recording can be referred to as a recordingprocessor. Also, the pickup 140, the RF AMP 130, the DSP 120 and the ANcodec 110 operating during playback can be referred to a reproductionprocessor.

[0069]FIG. 7 shows the relationship between still picture data and stillpicture group information, in which the information for a plurality ofstill pictures (e.g., 64 maximally) having the same attributes isrecorded in the respective still picture group (GVOB) information 201.The number of the still pictures forming each still picture group isdetermined such that it is within the limit of the maximum number ofstill pictures. Each still picture group information 202 includes stillpicture group general information and information for the respectivestill pictures and is information for still picture data 203 composed ofvideo parts and video or audio parts in a sequence of bitstreamsrecorded. The still picture group general information has the startaddress of the corresponding still picture group.

[0070] Also, as information for the respective still pictures, stillpicture information having original audio data exists in the form of mapinformation including video part information for video parts and audiopart information for audio parts. Here, a video map and an audio map fora still picture have the same identification information. If the stillpicture information is includes only a video part, it exists in the formof a map having only the video part information. In the still picturegroup information 202, virtual deletion information for virtuallydeleting both a still picture and original audio data added thereto ispresent. Here, still picture data is recorded in a VOB.

[0071]FIG. 8 shows the relationship between additional audio data addedto a still picture and additional audio group information according tothe present information, in which additional audio group (GAOB)information 211 includes information for additional audio data recordedin units of a plurality of additional audio groups. Additional audiogroup information 212 has additional audio group general informationcontaining the start address of the corresponding additional audio groupand audio maps (AMAPs) following the sequence of additional audio data.The information for additional audio data 213 including an additionalaudio part of a still picture is recorded in each additional audio map,inclusive of size information of the additional audio data thereof.Also, the additional audio group information 212 includes virtualdeletion information for virtually deleting the respective audio parts.

[0072]FIG. 9 shows the relationship between cell information (which canalso be referred to as playback information ) and still picture groupinformation, in which a cell is a logical unit in relation to indicationof a reproduction order. The cell information includes still picturegroup identification information (GVOB_ID), still picture reproductionstart identification information (START VOB_ID) of the correspondingstill picture group and still picture reproduction ending identificationinformation (END VOB_ID). The cell information may correspond to all thestill picture groups or may correspond to some of the still picturegroups which are intended to be reproduced.

[0073] The additional audio data are stored in a separate area from thestill picture data, that is, in a different file or in a different areaof the same file from or as that of the still picture data.

[0074] For example, in the case when the additional audio data is storedin a separate file from the still picture data, as shown in FIG. 7, GVOB#1, #2 and #3 having still picture data constitute a file. Also, asshown in FIG. 8, GAOB #1, #2 and #3 having additional audio dataconstitute a file. Thus, in the case of recording/reproducing actualstill picture or additional audio data, the still picture or additionalaudio data is accessed using the information of each file.

[0075] Alternatively, in the case when the additional audio data and thestill picture data are stored in one and the same file, GVOB #1, #2 and#3 and GAOB #1, #2 and #3 shown in FIGS. 7 and 8 constitute a file. Inconstituting the file in such a manner, the respective GVOBs and GAOBsmay be mixed in the recording order, for example, in the order of GVOB#1, GVOB #2, GAOB #1, GVOB #3, GAOB #2 and GAOB #3. Otherwise, the GVOBsand GAOBs are coupled and arranged in each batch to constitute a file.

[0076]FIG. 10 shows the relationship among cell information, stillpicture group information and additional audio group information, fordesignating desired additional audio data in the additional audio grouprecorded in a separate area as well as original audio data as the audiodata added to a still picture. The cell information includes stillpicture group identification information (GVOB_ID), still picturereproduction start identification information (START VOB_ID) in thecorresponding still picture group and still picture reproduction endingidentification information (END VOB_ID). Video part information in theinformation for still picture group GVOB #1 may have information fordesignating additional audio data added to a still picture, that is,additional audio group identification information and additional audioidentification information in the corresponding additional audio group.For example, additional audio group identification information GAOB #jand identification information #2 indicating that the additional audiodata is the second audio map in the GAOB #j exist in the video partinformation for a still picture #2 of the still picture group GVOB #i.

[0077] In the present invention, when a plurality of still pictures arerecorded in a file and still pictures are deleted and fragmented inseveral parts by a user's request, to avoid an abrupt increase in fileextent information, a plurality of still pictures are grouped andmanaged at a still picture group level, and each still picture hasvirtual deletion information. Thus, even if a user deletes a stillpicture, the still picture is not actually deleted from the file butappears to be deleted since they are not reproduced according to thevirtual deletion information. In some cases, the user deletes stillpictures for the purpose of securing empty space (free area) forrecording new data thereon in addition to avoidance of reproduction ofdata. In this case, since the data is not actually deleted, the emptyspace cannot be secured just by using the virtual deletion information.If all of the still pictures in the still picture group information arevirtually deleted, they are actually deleted from the file in units ofstill picture groups, thereby securing a free area. In other words,since a still picture group is formed by a plurality of still pictures,a considerable amount of free space is produced by deleting the same.

[0078] As shown in FIG. 11, if a still picture deletion command is inputby a user through an input device 301 such as a key pad mounted on astill picture output device 302 or a remote controller, virtual deletioninformation out of the information for the corresponding still picturein the still picture group information is set to “1” indicative of avirtual delete state, without change in an actual still picture file304. Since there is no change in the actual still picture file 304, thefile area information for the still picture file is not increased. Thevirtual deletion information is commonly applied to the original audiodata added to the still picture. In other words, if a still picture isvirtually deleted, the original audio data is also considered to havebeen deleted. Here, if the virtual deletion information set to “1” iscleared to “0”, the still picture can be restored.

[0079] However, if additional audio data is added to a still picture,instead of the virtual deletion information (which can be referred to asfirst virtual deletion information) for a still picture, as shown inFIG. 12, the virtual deletion information in additional audio groupinformation (which can be referred to as second virtual deletioninformation) can be used. If a still picture deletion command is inputby a user through an input device 31 1, virtual deletion information forthe corresponding still picture in the still picture group informationis set to “1” indicative of a virtual delete state and virtual deletioninformation for additional audio data in the additional audio groupinformation 314 for the still picture is also set to “1”. Thus, thecorresponding additional audio data in an additional audio file 315, isnot actually deleted either. Here, if the virtual deletion informationset to “1” is cleared to “0”, the additional audio data can be restored.

[0080] Actual deletion of a file occurring in a still picture group oradditional audio group will be described with reference to FIGS. 13 and14. In other words, when all the information in a group is virtuallydeleted, the group can be actually deleted from a file.

[0081] As shown in FIG. 13, if a still picture deletion command, forvirtually deleting all still pictures in the information for a stillpicture group #2, is input by a user through an input device 321 andvirtual deletion information in the information for a still picturegroup #2 in the still picture group information 323 is set to “1”indicative of a virtual delete state, the information for a stillpicture group #2 in the still picture group information 323 is deletedso that updated still picture group information 324 is created and datafor GVOB #2 in a still picture file 325 is actually deleted to beallocated as a free area. Therefore, even if a plurality of stillpictures are deleted, a discontinuous section in a still picture file isdetermined by deletion of the entire group, so that the file areainformation is increased by a small amount. In FIG. 13, identificationnumbers for still picture groups are sequentially given again. However,if the identification numbers are expressly stored in the still picturegroup information, they can be retained as they are.

[0082] Similarly, data of an additional audio group file can be actuallydeleted. As shown in FIG. 14, virtual deletion information for thecorresponding still pictures in still picture group information 331 isset to “1” indicative of a virtual delete state by a still picturedeletion command, and the virtual deletion information of the entireadditional audio information of the information for a still picturegroup #3 in additional audio group information 332 corresponding to thestill pictures set to a virtual delete state, is set to a virtual deletestate “1”.

[0083] The information for the additional audio group #3 in theadditional audio group information 332 is deleted and updated additionalaudio group information 333 is created. Data for GAOB #3 in an actualaudio file 334 is deleted to be allocated as a free area. In this case,the file extent information is increased by a very small amount. In FIG.14, identification numbers for additional audio groups are sequentiallygiven again. However, if the identification numbers are expressly storedin the additional audio group information, they can be retained as theyare.

[0084]FIG. 15 illustrates the structure of still picture groupinformation according to the present invention, which includes stillpicture group general information and a still picture map table, and mayfurther include attribute information for a still picture such aspicture sizes or video encoding modes.

[0085]FIG. 16 is a table showing an example of the detailed contents ofstill picture group general information shown in FIG. 15, which includesGVOB_ID representing information for identifying a still picture groupin a still picture file, GVOB_S_ADR representing the start address offirst still picture data in the corresponding still picture group in thestill picture file, GVOB_Ns representing the number of still pictures inthe still picture group, GVOB_Ds representing the number of virtuallydeleted still pictures in the corresponding VOB group, and so on. IfGVOB_Ds and GVOB_Ns are equal to each other, the VOB group can bedeleted from a file. If GVOB_Ds is not stored expressly, it is checkedwhether all still pictures in the corresponding still picture group arein a virtually deleted state to then be actually deletable. Also, theidentification information GVOB_ID can be expressly recorded as a uniqueone for each still picture group in a still picture file or can besuggestively indicated in the order of still picture groups, that is,#1, #2, . . .

[0086]FIG. 17 illustrates the structure of the still picture map tableshown in FIG. 15. There are two types of maps; one is video maps VMAPsfor video parts and the other is audio maps AMAPs for original audioparts added to the still pictures. The order of maps is the same as thatof data of recorded bitstreams in a still picture file as shown in FIG.7. Thus, in the case when a still picture has only a video part, thereis only a video map. In the case when a still picture has original audiodata in addition to the video part, both a video map and an audio mapare recorded and are practically considered as one map using the sameidentification information.

[0087]FIG. 18 is a table showing an example of the detailed contents ofa video map in the map table shown in FIG. 17, containing MAP_TYindicating the type of a corresponding map and represented by a binary“0” in the case of a video map for a video part, VOB_ID indicatingidentification information for the video part and ranging from 1 to 64in this embodiment. Also, VOB_ID can be expressly indicated orsuggestively indicated in the recording order, that is, #1, #2, #3, . ..

[0088] Also, the video map contains V_DELETE which is a binary valueindicating deletion or non-deletion of a VOB, that is, indicating that aVOB is not deleted if the value thereof is “0” and that the VOB isvirtually deleted if the value thereof is “1” V_PART_SZ indicating thesize of a video part, GAOB_ID which is identification information of anadditional audio group, the value of which exists if a still picture hasadditional audio data, and the value of which is “0” if a still picturedoes not have additional audio data, and AOB_ID which is identificationinformation of additional audio data in an additional audio group if astill picture has additional audio data, and the value of which is “0”if the still picture does not have the additional audio data.

[0089] Here, V_DELETE represented by a binary value “1” indicates that astill picture is virtually deleted. Thus, if the still picture hasoriginal audio data, the original audio data is also considered to havebeen virtually deleted. This is because original audio data solelyexisting after the still picture is deleted as being meaningless. Also,VOB_ID and V_PART_SZ can be referred to as still picture positioninformation, and GAOB_ID and AOB_ID can be referred to as additionalaudio connectivity information.

[0090]FIG. 19 is a table showing an example of the detailed contents ofan original audio map, containing MAP_TY indicating the type of acorresponding map and represented by a binary value “1” in the case ofan audio map for an audio part, A_PBTM indicating the playback time ofan audio part and A_PART_SZ indicating the size of the audio part.

[0091]FIG. 20 illustrates the structure of additional audio groupinformation for a still picture according to the present invention,containing additional audio general information and an additional audiomap table for the still picture. Also, additional audio attributeinformation for the still picture may be further included.

[0092]FIG. 21 is a table showing an example of the detailed contents ofadditional audio general information for a still picture, shown in FIG.20, containing GAOB_ID indicating identification information for anadditional audio group in an additional audio file, GAOB_S_ADRindicating the start address of the first additional audio data in thecorresponding additional audio group in the additional audio file, andGAOB_Ns indicating the number of additional audio parts contained in theadditional audio groups. GAOB_ID can be expressly indicated orsuggestively indicated in the recording order.

[0093]FIG. 22 illustrates the structure of an additional audio map tableconsisting of n additional audio maps for additional audio parts shownin FIG. 20.

[0094]FIG. 23 is a table showing an example of the detailed contents ofthe additional audio map table for the still picture shown in FIG. 22,containing AOB_ID indicating identification information for a specificaudio part in an additional audio group and ranging from 1 to 64 in thisembodiment, A_DELETE indicating whether an additional audio part isvirtually deleted or not, A_PBTM indicating the playback time ofadditional audio data and A_PART_SZ indicating the size of additionalaudio data such as the number of sectors. Here, AOB_ID can be expresslyindicated or suggestively indicated in the recording order, that is, #1,#2, #3, . . .

[0095]FIG. 24 is a table showing an example of the detailed contents ofcell information for a still picture, shown in FIGS. 9 and 10,containing S_GVOB_ID indicating identification information for a stillpicture group, S_VOB_ID indicating identification information for astill picture in which reproduction starts, and E_VOB_ID indicatingidentification information for a still picture in which reproductionends.

[0096]FIGS. 25A and 25B illustrate a flow chart showing a method forrecording a still picture according to a first embodiment of the presentinvention, that is, a method for recording a still picture and originalaudio data. First, it is determined whether a still picture or both astill picture and original audio data are recorded (step S101). Stillpicture group information is generated, identification for a stillpicture group is allocated, the number of still pictures in the stillpicture group is set to “0” and the start address of the still picturegroup in a still picture file is recorded (step S102). It is thendetermined whether a recording start signal of a still picture is inputby a user or not (step S103). If the recording start signal is input,the still picture is recorded in the still picture file, identificationinformation for the still picture is allocated to the still picturegroup information, the number of still pictures in the still picturegroup is increased by one and the size information of the still picturesis recorded in the video map (step S104).

[0097] It is determined whether or not a mode set by a user is forrecording both a still picture and original audio data (step S105). Ifyes, the audio data for the still picture is recorded following thecorresponding still picture on the still picture file and the audio sizeinformation is recorded in an audio map in the still picture groupinformation (step S106).

[0098] It is determined whether the number of still pictures recorded isthe maximum number possible to constitute the information for a stillpicture group (e.g., 64 maximally) (step S107). If the still picturegroup information is completed, the procedure returns to step S102 togenerate another still picture group information. Otherwise, theprocedure proceeds to step S103 to determine whether a recording startsignal of a still picture is input by a user or not.

[0099] If the mode set by a user is for recording only a still picturein step S105, step S106 is skipped and the procedure proceeds to step107 to record the next still picture. If the recording start signal of astill picture is not input by a user in step S103, it is determinedwhether or not to terminate recording (step S108). If it is determinedto terminate recording, cell information is recorded and the procedureends (step S109). Here, the cell information is created for every stillpicture group so as for all still pictures to be reproduced.

[0100]FIG. 26 is a flow chart showing a method for recording additionalaudio data after recording a still picture according to the firstembodiment of the present invention. First, additional audio groupinformation is generated, identification information for an additionalaudio group is allocated, the number of additional audio parts in theadditional audio group is set to “0” and the start address of the audiogroup is recorded in an additional audio file (step S201).

[0101] It is then determined whether the recording start signal ofadditional audio data is input by a user or not (step S202). If therecording start signal is input, a specific still picture to which theuser desires to add additional audio data is designated (step S203). Theadditional audio data is recorded in an additional audio file,identification information for additional audio data in the audio map ofthe additional audio group information is allocated, the number ofadditional audio parts in the additional audio group is increased byone, and the size information of the additional audio data in the audiomap is recorded (step S204). Although it has been described herein thatthe additional audio data is recorded in a different file from that ofthe still picture, the additional audio data can be recorded in aseparate area of the same file as that of the still picture.

[0102] Identification information for the still picture group of apredetermined still picture and identification information for the stillpicture are read and the information for the still picture, that is,identification information for an additional audio group for additionalaudio parts and identification information for additional audio data,are recorded in the video map for the predetermined still picture (stepS205).

[0103] It is then determined whether the number of additional audioparts in an additional audio group reaches N, that is, a maximum numberto constitute a group (step S206). If yes, the procedure goes to stepS201 to generate another additional audio group information. Otherwise,it is determined whether the recording start signal of additional audiodata is input by a user (step S202). If a recording start signal ofadditional audio data is not input by a user in step 202, the procedureis terminated.

[0104] Here, the step of designating a specific still picture (stepS203) may precede the step of determining whether or not a recordingstart signal of additional audio data is input by a user (step S202).

[0105]FIG. 27 is a flow chart showing a method for reproducing a stillpicture according to the first embodiment of the present invention, thatis, a method for reproducing a still picture and original audio dataadded thereto. Referring to FIG. 27, PGC information and cellinformation are read (step S301). Identification information for a stillpicture group to be reproduced, playback start identificationinformation and playback ending identification information are read fromthe cell information to read the still picture group information pointedto by the cell (step S302). Video map information for the video partcorresponding to the playback start identification information in theread still picture group information is obtained to read the size of avideo part, or both video map information and audio map information areobtained in the case of a still picture having original audio data toread the size of a video part and the size of an audio part (step S303).

[0106] The position of a desired still picture is calculated by the readvideo part information and video data located at the calculated positionis read and decoded to reproduce the still picture (step S304). Here,the position of a desired still picture is obtained by summing the startposition of a still picture group and the size of data preceding thedesired still picture. While the still picture is reproduced, it isdetermined whether original audio data is added to the still picture(step S305). If yes, the original audio data is read and decoded toreproduce the original audio data (step S306). Here, the readingposition of the original audio data is obtained by summing thecalculated position of the still picture and the size of a video part ofthe desired still picture. It is checked whether all still picturesbelonging to a cell are reproduced or not using the cell information andthen it is determined whether or not there is a still picture to bereproduced next (step S307). If yes, the information for the video partof the still picture to be reproduced next is read (step S303).Otherwise, the procedure is terminated. In the case when there are aplurality of series of cell information, this routine is repeated.

[0107] Here, the step of determining whether original audio data isadded to a still picture (step S305) may be performed directly after thestep of reading the still picture group information (step S302). This isbecause it is possible to determine that original audio data is added toa still picture in the case when an audio map for an audio part is addedsubsequently to a video map for a video part, in accordance with thestill picture group information.

[0108]FIGS. 28A and 28B illustrate a flowchart showing a method forreproducing a still picture according to a second embodiment of thepresent invention, that is, a method for reproducing a still picture, astill picture having original audio data, or a still picture havingadditional audio data. Referring to FIG. 28A, cell information is readfrom PGC information (step S401) and then still picture groupinformation pointed to by a cell to be reproduced is read (step 402).Information for the start position of a still picture group is read fromthe read still picture group information and the position of a desiredstill picture is calculated (step S403). Here, the position of a desiredstill picture is obtained by summing the start position of a stillpicture group and the size of data preceding the desired still picture.The video data is read and decoded in accordance with the positioninformation of the desired still picture to reproduce the still picture(step S404).

[0109] It is then checked whether additional audio data is present inthe still picture group information or not (step S405). If not, it ischecked whether there is original audio data (step S406). Here, thepresence of additional audio data in the map information for the videopart of the desired still picture to be reproduced can be determinedusing the identification information for an additional audio group andthe identification information for additional audio data. The presenceof original audio data can be known by determining whether there isaudio information (an audio map) in the map table of the desired stillpicture to be reproduced.

[0110] If there is original audio data in step S406, the read positionof the original audio data is calculated (step S407). Here, the readposition of the original audio data is obtained by summing thecalculated position of the desired still picture and the size of thevideo part of the desired still picture. Original audio data is readfrom the calculated position information of the desired still pictureand decoded to reproduce the original audio data (step S408) and theprocedure proceeds to step S411 as shown in FIG. 28B.

[0111] If additional audio data is present in step S405, that is, if theread identification information for the additional audio groupdesignated to the still picture and identification information for theadditional audio data are not “0”, the start position of the additionalaudio group is read from the additional audio group information tocalculate the position of desired additional audio data (step S409 inFIG. 28B). The position of desired additional audio data is obtained bysumming the start position of an additional audio group and the size ofthe additional audio data preceding the additional audio data having theidentification information for the desired additional audio data in theadditional audio group.

[0112] Additional audio data is read from the calculated positioninformation for the desired additional audio data and is decoded toreproduce the additional audio data (step S410). Then, it is determinedwhether there is a still picture to be reproduced next (step S411). Ifyes, the procedure returns to step S403. Otherwise, the procedure isterminated (step S411). In the case of reproducing a plurality of cells,the overall procedure is repeated.

[0113] Alternatively, instead of step 405 of determining whetheradditional audio data is present or not and step 406 of determiningwhether original audio data is present or not, it is first determinedusing the still picture group information read in step S402 whether thestill picture to be reproduced is a still picture having only a videopart, one having original audio data added thereto, or one havingadditional audio data added thereto. If the still picture has only avideo part, steps S403 and S404 are performed. If the still picture hasoriginal audio data, steps S403, S404, S407 and S408 are performed. Ifthe still picture has additional audio data, steps S403, S404, S409,S410 and S411 are performed.

[0114] Further, according to another aspect of the present invention,before reproduction, a reproduction mode is set by interfacing with auser to determine whether only a still picture is to be reproduced, botha still picture and original audio data are to be reproduced, or both astill picture and additional audio data are to be reproduced.

[0115]FIG. 29 is a flow chart showing a method for reproducing a stillpicture according to a third embodiment of the present invention, thatis, a method for reproducing data in the case when virtual deletioninformation in a still picture is set to a virtual delete state.Referring to FIG. 29, PGC information and cell information are read(step S501). Identification information for a still picture group to bereproduced, playback start identification information and playbackending identification information are read from the cell information toread the still picture group information pointed to by the cell (stepS502). Video map information for the video part corresponding to theplayback start identification information in the read still picturegroup information is obtained to read the size of the correspondingvideo part and the virtual deletion information (step S503).

[0116] When it is determined that the virtual deletion information isset to a virtual delete state, the still picture set to the virtualdelete state should not be reproduced. Thus, reproduction is skipped andthe procedure proceeds to step S508.

[0117] If the virtual deletion information is not set to a virtualdelete state in step S504, the position of a desired still picture iscalculated by the read video part information and video data located atthe calculated position is read and decoded to reproduce the stillpicture (step S505). Here, the position of the desired still picture isobtained by summing the start position of the still picture group whichincludes the desired still picture and the size of data preceding thedesired still picture. While the still picture is reproduced, it isdetermined whether audio data is added to the still picture (step S506).If yes, the audio data is read and decoded to reproduce the audio data(step S507). Here, two types of audio data are added to a still picture,that is, original audio data recorded with video data of the stillpicture and additional audio data added after recording. Either type orboth types of audio data may exist. If both types of audio data exist,the additional audio data is automatically reproduced or one type ofaudio data is selected by a user to then be reproduced.

[0118] Here, the read position of the original audio data is obtained bysumming the calculated position of the still picture and the size of avideo part of the desired still picture. The position of the additionalaudio data is obtained by summing the start position of the additionalaudio group indicated by the still picture group information and thesize of additional audio data preceding additional audio data havingidentification information for the additional audio data in theadditional audio group information.

[0119] It is checked whether all still pictures belonging to a cell havebeen reproduced or not using the cell information and then it isdetermined whether or not there is a still picture to be reproduced next(step S508). If yes, the information for the video part of a stillpicture to be reproduced next is read (step S503). Otherwise, theprocedure is terminated. In the case of reproducing a plurality ofcells, the overall procedure is repeated.

[0120]FIGS. 30A and 30B illustrate a flow chart showing a method fordeleting data using virtual deletion information according to thepresent invention, in the case when a user intends to actually delete aspecific still picture and/or additional audio data. Referring to FIG.30, a deletion command for deleting a specific still picture is input bya user (step S601). In accordance with the deletion command, virtualdeletion information for a still picture in the corresponding stillpicture group information is set to a virtual delete state “1” (stepS602). It is determined whether virtual deletion information for allstill pictures in the corresponding still picture group information isset to a virtual delete state “1” (step S603). If virtual deletioninformation for all still pictures in the corresponding still picturegroup information is set to a virtual delete state “1”, thecorresponding still picture group is actually deleted from the stillpicture information and the still picture group information is updated(step S604). All of the data in the corresponding still picture group isactually deleted from a still picture data file and the area of thecorresponding still picture group is set to a free area (step S605).Other still pictures or moving pictures can be recorded in the free areaand this file area is updated in a file system.

[0121] It is determined whether the virtually deleted still picture hasadditional audio data (step S606). If yes, virtual deletion informationfor additional audio data in the corresponding additional audio groupinformation is set to a virtual delete state “1” (step S607). It isdetermined whether virtual deletion information for all additional audioparts in the corresponding additional audio group information is set toa virtual delete state “1” (step S608). If virtual deletion informationfor all additional audio parts in the corresponding additional audiogroup information is set to a virtual delete state “1”, thecorresponding additional audio group is actually deleted from theadditional audio information and the additional audio group informationis updated (step S609). All of the data in the corresponding additionalaudio group is actually deleted from an additional audio data file (stepS610).

[0122] As described above, according to the present invention, duringreproduction, a virtually deleted still picture is not reproduced, usingvirtual deletion information. Thus, recording areas can be preventedfrom being scattered when some data files are deleted at a user'srequest, thereby avoiding an abrupt increase in file extent information.

[0123] Also, original audio data added to a virtually deleted stillpicture can be virtually deleted using virtual deletion information, andadditional audio data corresponding to the still picture can also bevirtually deleted. A still picture or additional audio data virtuallydeleted in units of groups is actually deleted from a file so that afree area for recording new data can be secured.

[0124] Further, a large number of still pictures, original audio partsadded thereto and additional audio data can be recorded using a minimumamount of information. During reproduction, data can be displayed andedited in units of still pictures. Also, it is possible to confrontafter-recording of audio data using the additional audio data. Videomaps and/or audio maps for still pictures can be formed in a recordingorder of bitstreams, thereby allowing effective management ofinformation.

What is claimed is:
 1. A recording medium, comprising: a plurality ofstill pictures; first virtual deletion information for the stillpictures, wherein the first virtual deletion information is indicativeof whether a corresponding one of the still pictures is currentlyreproducible; and still picture group information for separating thestill pictures into groups, wherein the still picture group informationincludes a start position of each still picture group and sizes of therespective still pictures within the still picture group, wherein thestill picture group information includes for each still picture group astill picture group identifier, a start address of one of the stillpictures in the corresponding still picture group, a number of stillpictures within the corresponding still picture group, and a number ofvirtually deleted still pictures in the corresponding still picturegroup.
 2. The recording medium according to claim 1, wherein the stillpicture group information includes video map tables for each of thestill pictures, and each video map table comprises a type of a video mapfor a video part, a video part identifier, the first virtual deletioninformation for the corresponding still picture, a size of the videopart, an information identifier of an additional audio group if oneexists, and an identifier of additional audio data in the additionalaudio group if the corresponding still picture has additional audio dataassociated therewith.
 3. The recording medium according to claim 1,wherein each still picture comprises a video part and at least some ofthe still pictures comprise an original audio part, the original audioparts are recorded consecutively after the corresponding video parts,and neither the video part nor the original audio part of thecorresponding still picture are reproduced if the first virtual deletioninformation thereof is set to the virtual delete state, and the stillpicture group information comprises for each original audio part, a typeof an audio map for an audio part, a playback time of the audio part,and a size of the audio part.
 4. A recording medium, comprising: aplurality of still pictures; first virtual deletion information for thestill pictures, wherein the first virtual deletion information isindicative of whether a corresponding one of the still pictures iscurrently reproducible; and a plurality of additional audio parts addedto the still pictures and connective information indicative ofconnectivity between the still pictures and the additional audio parts,wherein the connectivity information further includes identificationinformation for additional audio groups into which the additional audiodata are grouped and identification information for the additional audiodata in the corresponding additional audio groups, and additional audiogroup information includes additional audio group general informationcontaining the start position of additional audio groups into which theadditional audio parts are grouped and information relating to a numberof the additional audio parts in each additional audio group, andinformation for additional audio parts, the information for theadditional audio parts containing position information for theadditional audio parts in each additional audio group and second virtualdeletion information for the additional audio parts, wherein the secondvirtual deletion information is indicative of whether a correspondingone of the additional audio parts is currently reproducible, wherein theadditional audio group information for each additional audio groupincludes a type of an audio map for a corresponding one of theadditional audio parts, the second virtual deletion information for theadditional audio part, a playback time of the additional audio part, anda size of the additional audio part.